Types of Hot Mix Plants

Hot mix asphalt plants are equipment used to produce hot mix asphalt and are widely used in road construction and maintenance projects. Their primary function is to mix asphalt, aggregate and other additives in a specific ratio to produce an asphalt mixture that meets project requirements. Hot mix asphalt plants can be categorized based on mixing process, mobility and production capacity.

The following are the main types of hot mix plant and characteristics:

I. By Mixing Process (Core Category)
1. Forced Asphalt Mixing Plant (Batch Type Hot Mix Asphalt Plant)
- Principle: Drying and mixing processes are separated, resulting in batch production. Aggregates are first dried and heated in a drying drum, then graded by screening equipment and fed into a forced mixing tank according to the mix ratio. Simultaneously, additives such as asphalt and mineral powder are added in proportion. The mixture is then forced into a uniform mix by blades in the mixing tank before discharge.
- Features: High mixing uniformity (especially suitable for specialty mixtures such as modified asphalt and SMA), high mix accuracy, and flexible grading adjustments. However, the plant is complex (requiring separate systems for drying, screening, and mixing), resulting in high equipment costs and slightly higher energy consumption.
- Applicable Scenarios: Projects requiring high quality of mixed materials, such as expressways and first-class highways, or those requiring the production of specialized asphalt mixtures.

2. Drum Mix Asphalt Plant (Continuous Asphalt Mixing Plant)
- Principle: Drying and mixing are performed continuously within the same drum. Cold aggregate enters the inclined drum, where it is heated and dried by a burner. Simultaneously, hot asphalt is sprayed into the center of the drum. Aggregate and asphalt are continuously mixed as the drum rotates, leading to continuous discharge.
- Features: Simple structure (no independent screening or forced mixing systems), low equipment cost, and low energy consumption; however, mixing uniformity is somewhat poor (especially in the coating of fine aggregate with asphalt), making it difficult to produce specialized mixtures, and limiting flexibility in adjusting mix ratios.
- Applicable Scenarios: Projects requiring moderate quality of mixed materials, such as second-class and lower highways, municipal roads, or small temporary projects.
 

II. By Mobility
1. Stationary Asphalt Mixing Plant
- Features: The equipment is fixedly mounted on a concrete foundation, has a large structure (including large components such as the silo, drying drum, and mixing system), has a high production capacity (typically ≥120 tons/h), and requires long-term site occupation.
- Applicable Scenarios: Large-scale projects (such as highway sections) and centralized urban asphalt mixture production bases requiring long-term, stable supply.
2. Mobile Asphalt Mixing Plant
- Features: Core equipment (drying drum, mixing tank, small silo, etc.) is integrated onto a tire or track chassis, allowing for complete transport and installation and disassembly (complete within a few hours). The production capacity is medium (40-120 t/h).
- Applicable Scenarios: Small and medium-sized projects (such as rural roads and municipal maintenance), projects requiring frequent relocation, or temporary emergency production.
3. Semi-Mobile Asphalt Mixing Plant
- Features: A cross between fixed and mobile asphalt mixing plants, major components (such as silos and mixing systems) require disassembly and transportation, and on-site assembly (requiring a simple foundation). The production capacity is high (80-200 t/h), and the relocation cost is lower than that of fixed asphalt mixing plants.
- Applicable Scenarios: Medium-sized projects requiring periodic relocation (such as cross-regional highway construction), balancing production efficiency and relocation flexibility.
 

III. By Production Capacity (Auxiliary Classification)
- Small-sized asphalt mixing plants: ≤40 t/h, suitable for rural roads and small-scale maintenance;
- Medium-sized asphalt mixing plants: 40-120 t/h, suitable for municipal roads and secondary highways;
- Large-sized asphalt mixing plants: 120-320 t/h, suitable for highways and large industrial parks;
- Ultra-large asphalt mixing plants: ≥320 t/h, used for extra-large projects or centralized supply bases.
 

In summary, forced (intermittent) and drum (continuous) hot mix asphalt plants are the primary classifications based on core processes, while mobile and fixed asphalt mixing plants are categorized based on mobility requirements. In actual application, the selection should be based on a comprehensive consideration of project scale, quality requirements, and site transfer requirements.